exports.gt = function(op1, op2){
    return op1 > op2;
}

exports.ge = function(op1, op2){
    return op1 >= op2;
}

exports.lt = function(op1, op2){
    return op1 < op2;
}

exports.le = function(op1, op2){
    return op1 <= op2;
}

exports.eq = function(op1, op2){
    return op1 == op2;
}

/*
 * 判断字符串pattern是否在target字符串中。其中允许使用一个*作为任意字符串。即
 * "*abc" : 以abc作为结尾
 * "abc*": 以abc作为开头
 * "*abc*": 包含abc
 */
exports.like = function(pattern, target){
    var p = new RegExp(pattern);
    return p.test(target);
}
